The Basis of Early Christian theism is a textbook about early Christianity and the belief in various gods. Theism is broadly defined as the belief in the existence of a supreme being or deities. In common parlance, or when contrasted with deism, the term often describes the classical conception of God that is found in monotheism (also referred to as classical theism) — or gods found in polytheistic religions—a belief in God or gods without the rejection of revelation as is characteristic of deism.